Effects of cryopreservation on mitochondrial function and heterogeneity, lipid raft stability and phosphatidylserine translocation in koala (Phascolarctos cinereus) spermatozoa.
Reprod Fertil Dev
; 19(7): 850-60, 2007.
Article
en En
| MEDLINE
| ID: mdl-17897588
ABSTRACT
Koala sperm mitochondria were examined by cryomicroscopy using the fluorescent probe JC-1, which distinguishes high (red) and low (green) mitochondrial membrane potential (MMP). At normal body temperature, approximately 70% of live and untreated spermatozoa exhibited high MMP whereas <3% of live untreated spermatozoa exhibited low potential. A third class, in which single midpieces contained mixed mitochondrial populations, was also detected. Heterogeneity was noted in the level of MMP between individual koalas, individual spermatozoa and even between mitochondrial gyres within single midpieces. MMP of the live sperm population was not significantly affected by glycerol but was suppressed by freezing and thawing treatments. After thawing, MMP declined significantly during rewarming, especially as the temperature increased from 5 to 35 degrees C. The distribution of the ganglioside GM1 was examined using fluorescent-labelled cholera toxin B. In fresh, untreated koala spermatozoa GM1 was detected on the head and midpiece, but not on the principal piece. No significant redistribution of GM1 was observed after chilling and cryotreatment. Phosphatidylserine translocation across the plasma membrane was examined using fluorescent-labelled annexin V. Few fresh spermatozoa exhibited phosphatidylserine translocation (approximately 1%); this was not increased by chilling or cryopreservation, thus implying that cryotreatment had little effect on plasma membrane lipid asymmetry.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Espermatozoides
/
Crioprotectores
/
Microdominios de Membrana
/
Phascolarctidae
/
Potencial de la Membrana Mitocondrial
/
Mitocondrias
Límite:
Animals
Idioma:
En
Revista:
Reprod Fertil Dev
Asunto de la revista:
MEDICINA REPRODUTIVA
Año:
2007
Tipo del documento:
Article
País de afiliación:
Australia